Study of Oxytocin in Autism to Improve Reciprocal Social Behaviors

Inclusion Criteria: * Be between the ages of 3 years 0 months and 17 years 11 months at the time of randomization * Be diagnosed by clinician experienced in assessment of ASD with autistic disorder, Asperger's syndrome, or PDD-NOS using DSM-V-TR criteria * Must have clinical diagnosis of ASD confirmed using the Autism Diagnostic Observation Scale (ADOS, Lord et al., 2001) * Must have clinical diagnosis of ASD confirmed using the Autism Diagnostic Interview-Revised (ADI-R, Rutter, 2003). ASD criteria proposed by Risi (2006). Specifically, subject must be within 1 point of autism criteria on both social and communication domains of the ADI or meet autism criteria in one of these ADI domains and come within 2 points of autism criteria in the other * Have a guardian who is able to provide informed consent * If cognitively able, subject must be able to provide informed assent/consent Exclusion Criteria: * Have a known diagnosis of Rett Syndrome or Childhood Disintegrative Disorder, or have marked sensory impairment such as deafness or blindness * Have active cardiovascular disease or renal disease that is not controlled by medication * Subjects who are pregnant, lactating, or who refuse to practice contraception if sexually active * Subjects who have had changes in allied health therapies, behavioral or educational interventions within the two months prior to randomization other than those associated with school holidays * Subjects who have had changes in psychiatric medications within 4 weeks of randomization * Subjects who have had previous chronic treatment with oxytocin * Subjects who have caretakers who are unable to speak English, be consistently present at visits to report on symptoms, or are otherwise judged as unable to comply with the protocol by the data collection site team * Subjects with active seizures within the 6 months preceding screening or baseline -added part way through study in response to subject death.